mfhilo

[Mark Sponsler]

Hello,
I'm trying to use mfhilo and am having problems.  Likely a deficiency on
my part. Any help or nudge in the right direction would be appreciated.

I've downloaded and installed GrADS 2.0.a5.oga.4 on Wind XP in an attempt
to get access to mfhilo.  Normal scripts work fine using it.

I've consulted the wiki here: http://opengrads.org/doc/udxt/libmf/
and constructed a crude attempt to access the function:

'open file.ctl'
'set lat'
'set long'
'set gxout contour'
'd prmslmsl/100'

no problems so far, then...

 'result = mfhilo (prmslmsl/100) CL,h|l'

    minmax = sublin(result,1)

    say 'minmax = 'minmax

Receive error
Sytax Error:  Invalid operand
'mfhilo' not a variable or function name

Does anyone have a example or some guidance on how to use this function?